If you define your module multiple times, you should define it in this order:

First define should be like

angular.module('app.sources', []);

(with [ ])

Subsequent defines should be like

angular.module('app.sources');

(without [ ])

Important: Declaration order is important - definition with [ ] should go first.

Check that module is defined only once.
You may have forgotten to rename module after copy-paste. Check src for string like

angular.module('app.sources', []);

Check your'ng-app'. Better to use only one of these with name like ng-app='app' (In other words do not define multiple unnamed ngApp directives)

Is your controller's syntax correct for your AngularJS version?

(There is a difference between definition in Angular 1.0.x and 1.2.x and higher. With Angular versions greater than 1.3.x, you cannot declare a global constructor function and use it with ng-controller)

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